Engelbert mueller



E. MUELLER."

ARTJHGIAL LEG. APPLICATION men AUG 2. 1918.

Patented @ept. 9, 1919.

INVENTOR WITNESSES UNITED STATES PATENT :orricn ENGELBER'I MUELLER, OF RESERVE TOWNSHIP, ALLEGHENYCOUNTY, PENNSYLVANIA.

, ARTIFICIAL LEG.

Specification of hetters Patents l Patentedsept 9, 1919.

' A ucatibamedau ust a, 1918. "SerialNm248D28.

To all whom it may concern Be it known that I, ENGELBERT Momma, residing at Reserve township, in the county of Allegheny and State of Pennsylvania,

a citizen of the United States, have invented or discovered certain 'newand useful Improvements in Artificial Legs,of which improvements the following is a specification.

My invention relates to artificial legs which include thigh and lower leg sections pivotally connected to each other to form a knee joint, and the object thereof is to provide an artificial leg wherein the lower leg sections may, when the wearer is walk ing, be brought to its forward position in" alinement with the thigh section Without the necessity of the wearer exerting, by his shoulder or otherwise, an intermittent. pull upon the leg-supporting body member. A

In the accompanying sheet of drawings,

which forms part of my specification, I.

have illustrated the preferred embodiment of my invention. Figure 1 is a perspective view of the artificial leg; Fig. 2 a vertical central sectional view to enlarged scale of the knee joint; the plane of section being perpendicular to the pivotal axis of the thigh and lower leg sections; and Fig. 3 sectional view taken on the line IIIIII, ig. 2. t l

Artificial legs of the character shown herein are for amputations above theknee joint. Their general construction is well known, the legconsisting of a thigh. section 1 and a lower leg section 2 pivotally connected at the knee joint to the thigh section, the two leg sections being provided withcooperating stops to limit particularly the forward" movement of the lower leg section.

As such legs are usually constructed, a cord engages the lower leg section at a point in front of the pivotal axis of the le g sections, and is attached to a leg-supporting body member in such a manner that, when a wearer in taking a step causes the lower leg to swing backwardly, he may, byexerting an upward pull upon the cord before placing the footupon the ground, cause the lower leg to again swing forwardly into alinement with the thigh section. Usually.

the pull upon the cord for thus bringing the'lower leg section forwardly is exerted by the wearer raising his shoulder to a greater or less extent, and, this must be one for each step taken:

of such belt. p g 1 While the main portion of the weight of In the practice of my invention, the lower leg section is brought forwardly without alternately increasing and decreasing theeffectlve length of the cord section. This I accomplish by providing the upper portion of the lower'leg section with'two cord bearings, one arrangedlforwardly and, the other rearwardly of the" pivotaljaxis: of the leg sections, the former bearingbeing disposed at a greater radial distance fi-ornthe pivotal axis thanthe latter. "Extending around these hearings and preferably belowthe pivotal axis of the" legsection, I provide a a pin l. Through the upper portion of the ing member 3 attached to it,as by means of member 3 and the lower ends'5 of the thigh section 1, a suitable horizontalupivot 6 connects the two leg section to each other for the proper swinging movement of the lower leg section. The pivot or joint '6 may, as indicated, "consist of a bushing suitably held in placeas by means of a screw 8. The cord -bearings are preferably in the form of rollers 9 and 10, the forward roller 9 being'dis posed at a considerablygreater radial distance from the aXisof the pivot 6 than the rear roller 10. The cord 11 is connected 1 at both ends to a leg-supporting body memher, and extends around the cord bearings or rollers 9 andlO and below the axis of the pivot 6.; Preferably such member com- 1prises'abelt12 and shoulder-strap 13. One

end ofthe cord'll is attached to the front of the -belt12, and from such connection the cord extends downwardly in front of the thigh section, upwardly at the rear thereof,

and has its upper end attached to the rear the leg' is carried by the cord 11, a side strap 14 may connect the thigh section 1 to the belt "12 to carry a portion of the weight, or

such strap may be provided merely for the purpose of supporting the leg in case the cord 11 breaks.

plated herein, the thigh and lower. leg sections are provided wlth cooperating stops to limit the forward movement of the lower legsections. As shown herein the lower portion of the thigh a stop'l5 adapted to cooperate with a stop 16 formed on the upper end of the member 3. In walking,va wearer, in the usual manner, causes the lower leg rearw'ardly during the initial movement of taking a step; As the thigh section is moved forwardly, the weight of the leg, acting with greater leveragethrough the forward cord bearing 9 than throughthe rearward bearing 10, causes the lower leg section to gradually, and vnotfjerkily, move into alinement with n the thigh section. This straightening of the leg is accomplished, as already explained,

'K-without' the wearer exerting a pull upon the cord 11, as by raising his shoulder, or otherwise.

According to the provisions of the patent statutes, I have described the principle and section is provided with section to swing operation of my invention together with the leg construction which *I now consider to represent the best embodiment thereof. As is.us ual in-legs of the; sort ,contem-' H 'owever, I desire to have it understood that, withinthe' scope of the appended claim, my invention may be practised withother forms of a construction than that particularly shown herein,

I claim as my invention:

In an artificial leg, the combination of aleg-supporting body member, thigh and lower. leg sections pivotally connected to each other, said lower leg section being provided with two cord bearings arranged one forwardly and the other rearwardl of the pivot axis of the'leg sections, the forward bearing being at a greater radial distance from said axis than the rearward bearing, and a cord extending around said bearlugs and having its opposite ends attached to said body member.

In testimony whereof I have hereunto set my hand. i ENGELBERT MUELLER. Witnesses: v

G. G. TRILL, PAUL N. CRITCHLOW. 

